Packing material has been utilized for creating liquid tight seals on shafts in submarines including stern planes and rudder rams, as well as other military and industrial applications. Typically, the V-pack material is provided in rings having an interior opening that is slightly smaller than a cross-section diameter of a shaft onto which the V-packs are seated. Previously, the V-pack is provided in a ring of material having a top, shoulder, and bottom. The bottom of the V-pack forms a concave region. To create a shaft seal, a plurality of V-pack rings are slid onto the shaft and stacked against one another such that the top of each successive ring is seated into the bottom concave region of the previous ring. When a shaft seal needs to be rebuilt without removing the shaft, the rings have previously been cut in a diagonal direction and arranged around the shaft. With a single diagonal cut, it is difficult to create a sound seal as the free ends of the cut material tend to overlap one another and ride up on each other. Such overlapping and riding-up characteristics may cause premature failure of the seal. As multiple rings of V-pack material are stacked against one another to create the seal, overlapping ends can cause pockets of air to be trapped between the layers of V-packing. The expansion of air within the shaft can unseat a shaft seal over time with temperature and pressure changes, especially when diving and surfacing in submarines. Moreover, if the free ends of the V-pack material do not seat properly about the shaft, then a liquid tight seal is not achieved and seawater may migrate from one end of the shaft to the other.
By way of example, there are several publications that are directed towards various types of seals and rings.
U.S. Pat. No. 1,359,170 to A. L. Hatfield discloses a split packing ring. FIG. four of Hatfield shows the ring being split on a diagonal cut. A shaped notched 13 is shown in FIG. 7. U.S. Pat. No. 1,899,630 to V. E. Nelson discloses an oil retaining packing for rods and shafts. FIG. 3 shows the ring 16 that is split.
U.S. Pat. No. 2,017,615 to V. A. Bary discloses a packing for rotary shafts. The invention includes extensions and complementary recesses which receive the extension as shown in FIGS. 2-4.
U.S. Pat. No. 2,098,992 to J. M. Bandish discloses a packing ring. The packing includes rings 19, 20, and 21 which have diagonal cuts.
U.S. Pat. No. 2,553,750 to P. I. Cole discloses a packing ring. FIGS. 3-4 show packing arranged in opposite directions.
U.S. Pat. No. 2,692,152 to G. R. Tremolada discloses a split packing cartridge. The cartridge has a diagonal cut which is vertical at the bottom as shown in FIGS. 2-3.
U.S. Pat. No. 2,706,665 to C. W. Showalter discloses a packing for rods or shafts. FIGS. 3, 5, 6 show differently shaped cut ends.
U.S. Pat. No. 2,910,332 to T. D. Madsen discloses composed packing rings, particularly in piston rings for internal combustion engines. FIGS. 1-2 shows stepped ends.
U.S. Pat. No. 3,068,017 to R. A. Prosser discloses a high pressure packing adaptor. FIGS. 1-3 appear to show arrow shaped ends on the packing.
U.S. Pat. No. 3,169,776 to M. D. Felt discloses multiple purpose self-loading machinery packing. FIG. 1 shows a diagonal shaped end 17.
U.S. Pat. No. 3,171,661 to H. Blair et al discloses a “V” packing with insert and method of making the same. FIG. three shows a unique cross-section for the “V” packing.
U.S. Pat. No. 3,627,335 to Wheeler discloses a packing member. A packing member comprises an annular body having inner and outer sealing lips extending from one of its ends and from a point near its axial center, respectively. A plurality of holes extends axially into the body from equally spaced points along a circle concentric with the body. The member may be split along a line extending through at least two angles axially of the body, if desired. FIG. 6 shows a second embodiment which appears to have an arrow shaped end.
U.S. Pat. No. 4,818,209 to Petersson et al. discloses a mould and sealing ring. The sealing portion and the reinforcing portion constitute two portions positioned adjacent each other on each side of the connection surface in the axial direction of the ring for dividing the ring into a portion which is inactive from the sealing point of view and is active from the forming and locking point of view and a portion which is active from the sealing point of view is substantially inactive from the forming and locking point of view.
U.S. Pat. No. 3,861,691 to Wheeler discloses a packing member. A packing member comprises an annular body having inner and outer sealing lips extending from it. A plurality of holes extends axially into the body from spaced points along a circle concentric with the body. The member may be split along a line extending through at least two angles axially of the body, if desired.
U.S. Pat. No. 3,955,673 to Fosness discloses a rotary shaft packing replacement kit. A repacking kit for replacement of fluid seals for devices such as pumps is described. The kit comprises a plurality of preformed, oversized circular split rings having a specified configuration. The rings assume a helical shape around the shaft to be sealed and each is cut to size in a single step.
U.S. Pat. No. 4,398,731 to Gorman et al. discloses a Y-interlock packing seal. The seals are stacked on one another such that the yoke portion is nested within the Y recess of a successive seal.
U.S. Pat. No. 4,576,384 to Azibert discloses a split mechanical face seal. The seals have complementary recesses and extensions.
U.S. Pat. No. 4,643,440 to Massey, Jr. discloses packing with compensating means. The compensating ring includes a tapered annular protrusion having wedge faces for contacting and urging the shaft sealing lip toward the shaft and contacting and urging the stuffing box sealing lip towards the stuffing box when an axially-directed force is applied to the packing. The compensator ring is adjustable in diametrical dimensions so that contact is maintained between the wedge faces and the sealing lips and an effective seal is provided even if wear occurs on the sealing ring adjacent to the movable shaft.
U.S. Pat. No. 5,377,999 to Gorman discloses a guilded split packing ring comprising a split in the circumference of the annular body defining a nose at one end and a cavity at the other end for matingly receiving the nose therein.
U.S. Pat. No. 5,695,201 to Wheeler discloses a packing member with reducing friction. FIGS. 6-7 show an embodiment of the Wheeler invention having a rounded end.
U.S. Pat. No. 6,116,573 to Cornette et al. discloses a packing system for valves. FIG. 6 appears to have angled ends which mate together.
U.S. Pat. No. 7,140,618 to Valls, Jr. discloses a socket with dual-functional composite gasket. FIGS. 4-8 show different extension and complementary recesses.
U.S. Pat. No. 7,303,179 to Bush et al. discloses a split packing follower for use with valves. The first and second members include complementary interlocking structures that are configured to mechanically couple the first and second members to form the packing follower.
U.S. Pat. No. 7,708,283 to Azibert et al. discloses a mechanical seal assembly. The seal assembly has mating segments with overlapping surfaces.
U.S. Publication No. 2010/0206162 to Blue discloses a ram bearing assembly seal assembly therefore and associated method. The split seal joins in an interface which appears to include angle cuts.
U.S. Publication No. 2010/0264597 to Sato et al. discloses a split mechanical seal. FIGS. 12A-C appears to show angled cuts forming an arrow which are inserted into an arrow shaped recess.
None of the aforementioned documents contemplates, singly or in any combination, an improved V-pack seal comprising a plurality of V-pack rings that are sliced in a unique bi-directional manner to create a superior seal with the ends of each V-pack ring being seated into a proper relationship to encircle the shaft without creating any air pockets.